Thanks. I'm actually not entering the PRC by air because I'm flying into Hong Kong, so the airline is not the problem. Its the Chinese border guards in Shenzhen that will make the call to accept the card or not. In my email to the embassy I made it clear that I was a US Citizen and that the statement on their website contradicts the US government's site.

I replied to their email explicitly asking if a US issued card without any entry endorsements can be used for entry into the PRC and that I'd like to be sure of the PRC Ministry of Public Security policy on the matter. Hopefully the person answering visa emails will forward my question to someone in the MPS for an answer.